Improvement in piston-packings



UNITED STATES ATENT OFFICE.

IMPROVEMENT IN PISTON-PACKINGS.

Sperification forming part of Letters Patent No. 2,211 5, dated April 5,1864.

To all lwhom -it may concern Beit known that I, JEROME 'WIIEELocK, ot'Worcester, in the county of Worcester, in the State of Massachusetts,have invented a new and useful Improvement in Steam-Pis t ms; and I dohereby declare that the following is a full, clear, and exactdescription of the construction and operation ot' the same, r ferencebeing had to the accompanying drawings, which make a part of thisspecilication, in which- Figure l is a longitudinal elevation showingthe edge of the packing-rings. Fig. 2 is an end view showing a part ofone ring. Fig. 3 is aeentral axial section of the same. Fig. 4 is anelevation ot' one ring separately, showing the inner surface of saidring.

Similar letters of reference indicate corresponding parts in the severalfigures.

My invention consistsin making a segmental packing ring of cast-iron,brass, or other metal, the segments being cast or made sepa rately, theends so arranged and fitted as to break joints, for the purposehereinafter more fully explained.

To enable others skilled in the art to make aid use lny invention, willproceed to describe its use and operation.

A represents a common pistonllead. B is a solid T-shaped ring fitting onthe head A. C is a follower screwed onto A, which, together with thering B and flange on piston-head A, form two separate annular grooves, aa. D E are segmental metallic packing-rings fitting loosely in theannular grooves a a. Each of these segments are formed separately withan -shaped cavity, c o', at one end, and correspondngtongue e c at theopposite end, which lit into each other for the purpose hereinafter morefully explained. g g are apertures through which the steam passes intothe grooves ce a to the under side of the packingrings D E, causing themto expand, and by their expansion to make a steam-tight joint. Betweenthe inner surface of the engine cylinder and the piston F is a holethrough which the piston rod passes, and is attached to the pistonvheadin the usual manner.

The operation is as follows: The piston being made as described, thering B :and segmental rings D E are turned to lit the enginecylinder.When steam is admitted. against the follower O, it also passes throughthe apertures g, causing' the ring E to expand, and, making asteam-tight joint, prevents the steam from escaping to the opposite sideof the piston. The pistonv having completed its stroke, steam isadmitted against the piston--head A, and passing through the aperturesg', causing the ring D to expand, and alternately each ring is expandedand relieved according as steam is admitted and discharged. The iiangeon the piston-head A and follower G are turned smaller than the rings,to allow steam to press against a portion of the outer surface of saidrings, (see Fig. 2,) causing theirinner surface to t closely against thesides of thel ring B, thereby preventing the escape of steam from theunder side ot' said rings. As the segmental rin gs wear, the innercircle is constantly becoming larger, thereby causing the segments toseparate by causing the tongues e c to slide in the cavities c c, (seeFig. 4,) and thus breakingjoints and ettectuallypreventing all escapeot' steam.

The principal advantages of the ring herein described over those now inuse are, first, a much stronger ring is obtained lthan when two ringsare used for the same purpose second, the ring being cast in segments,much labor and material aresaved, it being neces-l sary to finish onlythe inner surface and outer edge.

Having thus described my invention, what l claim as new and of myinvention herein, and desire to secure by Letters-Patent, is-

The segmental packingrings D E, constructed in the manner and for thepurpose set forth and described.

Witnesses: JEROME WHEELOCK.

H. W. FENNER, WM. ADAMS.

